In terms of precipitation, rainfall in Cusco ranges from 0.0 - 5.5 inches per month. January is typically the wettest month, when rainfall can reach 5.5 in. May is typically the driest time to visit Cusco when rainfall is around 0.0 in.
If weather is an important factor for your trip to Cusco, use this chart to help with planning. For those seeking warmer temperatures, October is the ideal time of year to visit, when temperatures reach an average of 55.4 F. Travelers looking to avoid the cold should look outside of June, when temperatures are typically at their lowest (around 50.0 F).